Add the frozen berries, chopped apples, clementine juice and 2tbsp of the sugar to a baking dish and mix with a spoon. (A slightly wider dish works well so the juices can bubble off and the crumble gets nicely golden).

In a large bowl mix together the flour and butter with your fingers, rubbing well until combined.

Add the oats and remaining sugar and rub again with your fingers.

Sprinkle this topping over the fruit, covering as much of it as possible.